In my case, I had to REMOVE a kext. My internal SATA drives were appearing as removable if I have this kext installed. I removed the kext and that fixed my problem.
http://www.tonymacx86.com/mountain-...-fix-sata-hd-removable-media-yes-problem.html
Hi everyone!
I was having the same problem: IOAHCIBlockStorageInjector had done the trick in Lion but not in Mountain Lion, and I had internal drives showing up as external, more specifically, the FAT32 a NTFS partitions of an internal hard drive (a third HFS+ one showed up as internal just fine).
The instructions above did not work, but maybe having done them before what I did afterwards was the solution, so the method that worked for me would be:
1. Go to System/Library/Extensions
2. Delete (or back it up somewhere else) the file IOAHCIBlockStorageInjector.kext
3. Run Kext Utility
4. Run Multibeast and select Drivers and Bootloaders>Drivers>Disk>3rd Party SATA and 3rd Party eSata (I'm using Multibeast for Mountain Lion so permissions are fixed by default)
5. Reboot. Nothing happened, the internal drives still showed up as external. But I noticed that the Time Machine icon had changed from blue to orange, and I didn't wanted that, so...
6. Run Multibeast again, and this time select Drivers and Bootloaders>Drivers>Disk>IOAHCIBlockStorageInjector.kext
7. Reboot: it worked this time, everything shows up as internal and Time Machine is back to blue.
The solution is proably simpler than this, and 3rd Party eSata probably has nothing to do with this, but these are the exact steps I followed and worked, after having tried all the other solutions found around here without success.
Let me know if it works for you!
Cheers,
Leo.
PS: I'm under a Gigabyte Z68MX-UD2H-B3 with F13 firmware and corresponding DSDT from the database.